On my 07 ultra I can move the touring pack back about an inch. Well in my case I can move it forward about an inch, but best I can tell I have only one adjustment. But if you are good with a drill I don't see why you couldn't create another hole for you touring pack bolts.
If I ma riding with my wife i don't usually use the backrest.

Probably a stupid question, but have you been to the dealer? It's almost guaranteed if you have a problem with something, others have it also. There may be adapters, adjusters or something already available.